Edelbrock carb problems

I am no carb expert but thought that it is time to learn because I am tired of spending $300 to get my caburators rebuilt. So I bought a used edelbrock 650 carb and decided to rebuild it. I have done plenty of bike carbs but never car, I cleaned it real goog and then put it back together with a little help form the manual and youtube. My problem is it starts but wont idle and it seam to be vapor locking. I have a Holley red series pump and a fuel regulator that is set on 5.5 psi. This carb is on a Cadillac 472 and it ran smooth with the original quadrajet but it was hard starting and leaking so I decided to go with an edelbrock because I am planing on running a new edelbrock intake later and it has an electric choke.

I would like to know if maybe I did something wrong to produce this issue or maybe a left somthing out. I was pretty careful to make sure I looked at how everything came apart and took my time putting it back together. the carb was real corroded so maybe that is the reason I am having problems but would like to get some advise from some experts.

 

Did you dip it or just use spray carb cleaner?It may have some clogged p***ages still.

 

I soked it, and then sprayed thru the p***ages with carb cleaner. maybe I shoud take it apart again and clean it again. I thought i cleaned it real good the first time.

 

Did you blow the p***ages out with air? I would trouble shoot the problem if it persists with Edelbrock Tech ***istance. They helped me huge when I initially set mine up. Go to the Edelbrock site and give them a call. They will be more than willing to help.
Jay

 

sounds like sticky floats - were they free when you ***embled them? did you set the drop and height properly?

 

you have a point maybe I should pull it apart and check for a clogged jet. do these carbs have an idle jets seperate from the main jets, maybe thats the problem and if it persists i will contact Edelbrock like you said.

 

the sticky floats sound like a problem I may be having. I did do a blow check on the new float and they were sticky and seamed to be hard to open. I will check this out again tonight.

 

I have three cars with Edelbrock's & one with a quadrajet.
Hate the Edebrocks love the quadrajet!

 

I would say that you have a float sticking.
You may also be running a carb that is too small. (Although it would idle fine) Are you using the Edelbrock intake also?
I believe that the smallest recommended carb for that engine is a 750. There are plenty of Cad professionals here that can get you strait if I'm off with that statement.

 

Make sure you blow out the top cover fuel p***ages , both needle seats and inlet . They seem to collect junk in there for some reason.

 

On an Edelbrock, or old Carter Carbs, the float level is set when you remove the top of the carb. That's also the way to change jets. Sometimes when the carb is taken apart, it is set down with the two floats down. This can bend the mechanism that is used to set the floats. Unlike a Holley, Edelbrock/Carter Carbs floats are set by bending a tab. Once bent, the top of the carb is held upside down and the height of the floats are measured with a ruler or a calliper. Once the float level is set, make sure to set the air-fuel mixture with the two large screws in front of the carb. Start by turning them all the way in (count the number of turns until seated). Then back them off one full turn. Once the carb is on the car, the car is running and warm, final adjustment of the air-fuel mix can be done. Edelbrock sends a very helpful instruction manual with their carbs. Even better is the Carter Carb Rebuilding book. If all else fails, ask an old Mopar racer. We've been running Carters for years. Good luck. Tom

 

Hey guys thanks for the info, the carb came off the 454 and the guy said it was a 650 but I have not check that out so maybe I should. how do you know if it is a 650 or a 750 carb. the carb came off a 454 andI just figured if it was on a 454 it would work with the 472. I am just hoping to save the money for a new intake and having this one rebuilt just taking off this intake and puting it on the new one when I get it. but if it wont work I have a small block that might like it.

 

Thanks Frustration for the pointers, i believe i set everything up right but the float seats for the floats seam to hang up is their any way to make them move more smoothly or are they designed to be tight. for example when you hold the top up and let the floats drop the seats dont drop is this a problem. I can blow them out with mouth but they are pretty hard to do so

 

never had an edelbrock---but you cant beat a quadrajet when they are right

 

The model number is on the front, p***. side of the carb. A 650 should be fine if it's a stock 472. Vapor lock is not a likely scenario. That's mosly a hot weather, hot engine issue that effects the fuel line. Not so much the carb itself. What symptom leads you to say vapor lock? Can you keep it running with the throttle; it just won't idle? I think the rebuild instruction have you set initial primary throttle plates to a slight gap. Did you do this?

 

This is the exact situation, I fire it up runs only on the thottle and runs rough then I run it for a minute or so then it quits and then it wont turn over. I then leave it and it will turn over fine later and start up again. never had this issue with the quadrajet on it but I am a novice at carbs (I usually hire it out but tired of it) I think I just have somthing set up wrong and just want advise because this is somthing I need to learn how to do.

 

I saved my original Q-jet off the 472 for a core if nothing else. Heck the engine started and ran fine on with that carb after sitting 18 years. Bought a new Edelbrock, but as stated in your original thread here - had to do again I would go Q-jet from Cad company. rebuilding a cheap Eldelbrock not something I would consider.

 

I had a similar problem and it was caused by **** clogging the screens of the seat, in your case I think if your needles are not moving freely they are probably getting stuck closed. Check your float at 7/16 when horn is upside down and 15/16 when floats drop, I learnt this when mine was running like **** and I had set the float at 7/16 but didn't realize that you need to make sure the drop is correct...check that the float setting measurements are correct for your carb. Make sure fuel pressure is 5 1/2 or less

 

Like I said, check the floats - could be **** in the seat under the needle - have had that happen a few times, also the floats should move freely, slightly bend the ears that the pin goes through until they are smooth and easy.

 

You did use a rebuild "kit" I trust? The kit comes with new inlet screens as well as inlet (float) valves. They give you both styles of screens; 1 larger one for the main inlet and 2 smaler ones for in each of the float valve bores. You use one or the other -not both. Your float valves should not be sticky if you put the new ones in that are supplied.
You're not dealing with old, stale gas are you? Modern fuel goes stale a lot sooner than it used to.
Also, it wouldn't hurt to make sure you're getting proper fuel delivery by testing for pump output. It could be a wonky pump, clogged line or inline filter. They will cause the problems you're describing.

 

The Edelbrock Performer(500 CFM,600CFM,750CFM is based off the Carter Compe***ion Series AFB 500CFM,625CFM,750CFM they are one of the easiest to set up once you learn them and here is a site you should use for your set-up:http://www.mymopar.com/downloads/carterafbtuning.pdf There are also two types of needle and seats used,later Carbs have a spring loaded needle and early models used a solid needle (some call these Hi-Flow) the spring loaded type was supposed to be better if used for any off-road use.

 

I bought a new rebuild kit at my local suplier so it is all new except the needles and jets. I did put in new float valves and seats but the float valve does not move real smooth. the kit I bought is not an edelbrock kit and did not have new screens so I cleaned the old ones. maybe its the kit but my supplier I trust he is not a Autozone so I usually trust the parts.

 

Jeff thanks for the link. it should help

 

I have found some carbs with wear on the tang that rides on the float needle. That will cause "catchy" movement. I inspect and polish that area on all rebuilds now.

 

Sounds like a vacuum leak to me!
What did you use for an adaptor to bolt your eddy on with?

 

I am using an edelbrock adapter plate with two gaskets. I was having som much problems I decided to put the quadrajet back on just to get it running again. I decided to talk to my friend who rebuilds these carbs alot and he said it sounds like still a float issue. I am thinking I am going to run the the quadrajet on the cadillac and then just use the edelbrock on my small block for my T. this will give me time to get the bugs out of the carb. thanks for the help I just need to take some time and learn more about rebuilding carbs to make them run right.

 

Here's some links for you.
http://www.crankshaftcoalition.com/...hester_Quadrajet_4MV_carburetor#Trouble_spots
http://www.vetteprojects.com/kstyer/quadrajet.htm

 

get a holley!

 

Pay particular attention to how the clip from the needle hooks on the float. Don't hook it thru the centre hole. If it is that way it can cause the needle to hang up and flood.

 

You did put the big jets in the front and the little ones in the back didn't you? The rear jets are smaller because the front ones have a mettering rod in them. If the rear jets are installed in the front and the engine starts vacuum will pull the metering into the jet shuting off the fuel.